Examples

Cadmium sulphate, CdSO_4, is known in several hydrated forms; being deposited, on spontaneous evaporation of a concentrated aqueous solution, in the form of large monosymmetric crystals of composition 3CdSO_4·8H_2O, whilst a boiling saturated solution, to which concentrated sulphuric acid has been added, deposits crystals of composition CdSO_4·H_2O.